In the dining room of the elegant, five-star Windsor Court Hotel in New Orleans, a striking painting by the English Victorian artist Richard Ansdell (1815-1885) adorns one wall. It shows a huge, and rather fierce-looking dog, perhaps a mastiff, sitting calmly but alertly in front of a little girl who has fallen asleep, quite innocently, in a wicker basket behind him. The painting is called “Keeping Watch.”

There are, I suppose, a few misguided cultures in the world that would not understand the picture at all, cultures where dogs are primarily items for gourmet degustation at the dinner table. But the remarkable thing is that, for most of the human race, the painting requires no explanation at all. It simply depicts what is: the fascinating, universally discussed, but incompletely understood relationship of affection and trust that connects the human race to canis familiaris, the domesticated dog.

There is still an ongoing scientific dispute about exactly when dogs became fully domesticated. Scientists generally agree that it almost certainly was not later than 7,000 B.C., but it might have been as early as 30,000 B.C. But for as long as humans have been interred in graves with their favorite belongings, or have been able to write about their lives, dogs and humans have been inextricably connected.

In America there are an estimated 55 million dogs that live with families as pets—or “animal companions,” to use the snarling politically correct coinage. Yet it is exactly the huge number of them that complicates our efforts to understand them through and through. We are so familiar with dogs, we so readily attribute to them human traits—it is called anthropomorphizing—that we often forget that they are actually animals. At the same time, in our rush to compensate for the sentimentality of anthropomorphizing, we sometimes go to the other extreme of thinking that dogs are just animals. They are not; they are animals whose habits and behavior cannot be extricated from the human society in which dogs have learned to live.

There is a basic scientific consensus that dogs evolved from wolves. Over a period of time, it is speculated, dogs came to hang around human communities, learned to get fed by being of service to humans—or perhaps just by looking cute—and, through millennia of selective breeding, began to lose their most wolf-like qualities. Their snouts became shorter, their brains became bigger—as ours became smaller—and they lost their interest in hunting in packs. At the same time, they seemed to develop an understanding of humans, a familiarity with human behavior, and an intuitive sensitivity to human emotions that endeared them in a special way to their human companions.

Despite all these obvious points, the scientific literature on dogs is remarkably scant. In TheWolf in theParlor, Jon Franklin reports the tragicomic story of one of the foremost authorities on the domesticated dog abandoning his field because he could not secure grants for serious research. The deciders of grants, it must be assumed, are as fond of dogs as the population as a whole; it’s just that they are not very interested in helping people do research on them. The benighted professor has now turned his attention to goats, which apparently are higher up the academic-grant food chain.

Franklin, a Pulitzer Prize-winning science reporter, writes perhaps the more readable of these two books. On the other hand, Alexandra Horowitz’s Inside of a Dog is more informative. It gives short shrift not only to anthropomorphism but to other myths, such as the assertion that dogs are color-blind (they are not). One of Horowitz’s most fascinating sections explains what, exactly, dogs are doing when they sniff the urination markings of other dogs. Generally, it turns out, dogs are sniffing up the details of the sexual history of other dogs who have left their mark. She breezily dismisses the notion that dogs look to us as part of their pack, or are always on the lookout for the alpha male.

Both authors have had dogs of their own, and both books are full of doggy tales, most of them sentimentally endearing. Franklin has, by far, the most dramatic story: He and his wife were saved from death because their dog smelled (or otherwise sensed) that a fire had broken out in a utility room and very rudely awoke them both in time to make an escape.